“The Walking Dead” prompted gasps across America on Sunday night when it was revealed that Carol was responsible for the deaths of Karen and David.

Even Melissa McBride, who plays the character, told AccessHollywood.com, she was — at first – surprised by the twist, but then, she remembered some interesting dialogue from earlier scenes in Season 4.

Those lines indicated that Carol, who spent much of Season 1 cowering under the threat of her husband’s fist, and Season 2 in a panic, followed by fear and mourning for her daughter, has seemingly turned to Teflon in recent episodes.

A woman who was a strong caretaker in Season 3, and had started to become a walker warrior, began Season 4 with an even greater confidence. She was flirting with Daryl Dixon (Norman Reedus) and calling him “Pookie,” running the prison canteen, teaching children how to use weapons, and when tragedy struck, she was first to insist that those with the virus were a threat dead – or alive.

In a new interview with Access, Melissa addressed the twist, as well as what is next for Carol now that Rick Grimes (Andrew Lincoln) knows her secret. Plus, Melissa shared how delighted she was by the fans’ reaction to the “Pookie” line in the season premiere.

AccessHollywood.com: We, as writers, always use the words ‘twist’ and ‘shock’ in headlines over TV, but with this episode — wow. When you read Carol was responsible for Karen and David, what did you think?

Melissa McBride: I was really surprised, but you know what? There was a lot… that Carol said in that council meeting. This season and these scripts, there’s just not a word wasted and so I was reading that and remembering that council meeting and how she behaved with the children and the urgency of everything and then when I read that it was actually Carol that killed Karen and David, I was really surprised sort of, but then not surprised. You know? …Just the words in the council meeting kept coming back to me — ‘If they die, they’re a threat. You die, you’re a threat.’

Access: You love coffee (she does! Check out Melissa’s Twitter page)… and there was a scene in Sunday’s episode where Hershel was digging through some drawers and pulled out a ‘Java Saves’ mug. Did you notice that?

Melissa: (Laughs) No, it was not my mug, but I thought that was great.

Access: When Carol goes out to fix the hose — is part of that guilt that makes her put her life in danger or is she, ‘I’ve got to protect these people at all costs, even if that cost is me.’

Melissa: Yeah, that’s what it is. I think she’s feeling confident that she can — in that circumstance — protect herself, if she has to. She’s keeping an eye out, but what her main motivation there is, [is] to get that water pumping again, because like she says, ‘We don’t’ know if we have a tomorrow.’ Rick says, ‘We’ll do it tomorrow,’ but you know, we can’t wait. Tomorrow may never come. She’s just determined… and she’s in a whole new mode this season.

Access: I talked to Steven Yeun ahead of Season 4, and he said they were really giving you the material you deserved… is kind of how he put it. He’s very impressed by you, by the way.

Melissa: I love him and the feeling is absolutely mutual.

Access: Going from that… What do you love about Carol this season? She’s take charge, flirting with Daryl, running a clinic for knives and all this kind of stuff.

Melissa: I’ve loved her since the beginning and I’m really just loving the progression, and it feels like a natural progression for her, given where she’s come from and the circumstances that she’s facing along with everyone else… She lost her daughter, she was kind of helpless when all of that was happening and I think she’s just really trying to make this right in her heart and in her mind and in the world. If she’s going to continue to survive — and she has the will to survive and the desire to survive — and I think that’s great, but she is just — she’s coming at it from a place, from everything she’s learned, you know? In the good stuff and the adversity. She’s just learned from the adversity and it’s making her stronger and more willful.

Access: When you have a guy like Rick figuring things out and learning something like this [that Carol killed Karen and David], does that put her in some danger? Obviously she saw Rick go to town on Tyreese. So how concerned would she be going forward, or is she so confident in what she did?

Melissa: She’s pretty steadfast in what she has done and she knows that… Well, first, she’s not combative, like Tyreese, [who] I think took the first swing in that, and I don’t think that’s gonna happen (laughs). But there is going to be fallout and consequences. But, it’s going to be very interesting and I cannot wait for people to see what’s coming after this.

Access: I think what some people will be most worried about is how will this affect ‘Caryl’ [Carol + Daryl]… because it doesn’t seem like Daryl would be down with this… But maybe he would…

Melissa McBride: I don’t know. That’s something we’re gonna have to wait and find out. … I don’t know. Would he? Would be down with it? Would he understand that’s… Still, it’s a hard thing to accept what she’s done, by even she herself. I’m sure, certain [she] feels remorseful about what had, in her mind, had to be done.

Access: Should we worry about Glenn? Would she do something to Glenn, do you think, had Rick not found out?

Melissa: I don’t know. … That’s a great question. A great question.

Access: Let’s go into some old material… The ‘Pookie’ line [between Carol and Daryl in the Season 4 premiere]. What was the reaction like and did it warm your insides to see what people thought of that?

Melissa: I love it. Of course, there were Twitter user names, ‘Pookie,’ ‘Pookie this,’ ‘Pookie that.’ … It was really fun. I love the fans and how they just play and get all excited. They’ll take any grain of anything and turn it into a loaf of bread. … But it’s great, you know. It holds them over and makes them happy and get excited.. I just love Carol and Daryl. I think they’re — they’re adorable to me. They’re very special to me.

Melissa: You know, I don’t know. We might have to — you asked me this the last time and we haven’t even revisited it since, he and I.

Access: What? Oh no! I love the idea of that!

Melissa: It’s only because this world is getting real… and there’s just no time for play anymore. No, it is fun. We will have to come up with… our first episode. That’s just the intro, so we’ll come up with our first episode sooner or later.